Efeito do cloridrato de verapamil, cloridrato de fluoxetina e paroxetina isolados e combinados com anfoteicina B contra Cryptococcus neoformans: estudo in vitro e in vivo / Effect of verapamil hydrochloride, fluoxetine hydrochloride and paroxetine alone and combined with amphotericin B against Cryptococcus neoformans: in vitro and in vivo study

Cryptococcus neoformans são leveduras que acometem principalmente indivíduos imunocomprometidos, podendo causar a meningoencefalite dependendo do estado imunológico do hospedeiro. Os tratamentos convencionais têm enfrentado grandes desafios. Dessa forma, o objetivo desse estudo foi avaliar os efeitos antifúngicos dos fármacos cloridrato de verapamil (CV), cloridrato de fluoxetina (CF) e cloridrato de paroxetina (CP) isolados e combinados com anfotericina B (AmB) contra C. neoformans. Foram determinados os valores de Concentração Inibitória Mínima (CIM) e Concentração Fungicida Mínima (CFM) de acordo com a técnica de microdiluição em caldo proposta pelo Comitê Europeu de Teste de Susceptibilidade Antimicrobiana (EUCAST). Posteriormente, foi avaliada a atividade sinérgica dos fármacos combinados com AmB (EUCAST). Os efeitos das CIMs e das concentrações sinérgicas selecionadas foram avaliados em biofilmes, quantificando a biomassa por cristal violeta e sua viabilidade por contagem de colônias (UFC/mL). Além disso, foram analisados os efeitos dos mesmos na cápsula induzida desta levedura. Os ensaios in vivo foram realizados em Galleria mellonella avaliando a toxicidade dos compostos e a eficácia por análise de curva de sobrevivência e também o efeito em concentração de hemócitos. Os fármacos CV, CF e CP apresentaram valores de CIM de 113, 9,6 e 41µg/mL, respectivamente, e quando combinados com AmB resultaram em vinte concentrações sinérgicas, e uma concentração de cada combinação foi eleita para os ensaios seguintes. CV reduziu a biomassa do biofilme em até 38%, já CF e CP reduziram a biomassa de 22-30% quando isolados, e as combinações reduziram até 35 % da biomassa. O CP diminuiu a viabilidade do biofilme em até 25 % e quando o CF e CP foram combinados com AmB a redução chegou a 11 %. Além disso, todos os fármacos isolados e combinados reduziram o tamanho da cápsula da levedura, de 48-72 %. Em G. mellonella os fármacos não apresentaram toxicidade, eficácia ou ação na concentração de hemócitos. Assim, os fármacos avaliados apresentaram potencial antifúngico frente C. neoformans em todos os ensaios in vitro, podendo ser considerados novas alternativas para o tratamento destes patógenos(AU)

Cryptococcus neoformans are yeasts that mainly affect immunocompromised individuals, and may cause meningoencephalitis depending on the immunological state of the host. Conventional treatments have faced major challenges. Verapamil hydrochloride (CV), fluoxetine hydrochloride (CF) and paroxetine hydrochloride (CP) were isolated and combined with amphotericin B (AmB) against C. neoformans. Minimum Inhibitory Concentration (MIC) and minimum Fungicidal Concentration (CFM) values were determined according to the broth microdilution technique proposed by the European Committee for Antimicrobial Susceptibility Testing (EUCAST). Subsequently, the synergistic activity of drugs combined with AmB (EUCAST) was evaluated. The effects of MICs and selected synergistic concentrations were evaluated in biofilms, quantifying the biomass by violet crystal and its viability by colony-forming unit analysis (CFU / mL). In addition, the effects of the same in the induced capsule of this yeast were evaluated. In vivo assays were performed in Galleria mellonella evaluating the toxicity of the compounds and the efficacy by analysis of survival curve and also the effect on hemocyte concentration. The CV, CF and CP drugs had MIC values of 113, 9.6 and 41 µg / mL, respectively, and when combined with AmB resulted in twenty synergistic concentrations, and a concentration of each combination was chosen for the following trials. CV reduced biofilm biomass to 38%, while CF and CP reduced biomass to 22-30% when isolated, and combinations reduced to 35% of biomass. CP decreased biofilm viability to 25% and when CF and CP were combined with AmB the reduction reached to 11%. In addition, all drugs isolated and combined reduced the size of the yeast capsule to 48-72%. In G. mellonella the drugs did not present toxicity, efficacy or action in the concentration of hemocytes. We suggest that the liposolubility of the compounds has been a limiting factor in vivo analyzes. Thus, the evaluated drugs presented antifungal potential against C. neoformans in all in vitro assays, and could be considered new alternatives for the treatment of these pathogens(AU)

A review of network-based approaches to drug repositioning.

Experimental drug development is time-consuming, expensive and limited to a relatively small number of targets. However, recent studies show that repositioning of existing drugs can function more efficiently than de novo experimental drug development to minimize costs and risks. Previous studies have proven that network analysis is a versatile platform for this purpose, as the biological networks are used to model interactions between many different biological concepts. The present study is an attempt to review network-based methods in predicting drug targets for drug repositioning. For each method, the preferred type of data set is described, and their advantages and limitations are discussed. For each method, we seek to provide a brief description, as well as an evaluation based on its performance metrics.We conclude that integrating distinct and complementary data should be used because each type of data set reveals a unique aspect of information about an organism. We also suggest that applying a standard set of evaluation metrics and data sets would be essential in this fast-growing research domain.

Drug repositioning and repurposing: terminology and definitions in literature.

Drug repositioning and similar terms have been a trending topic in literature and represent novel drug development strategies. We analysed in a quantitative and qualitative manner how these terms were used and defined in the literature. In total, 217 articles referred to 'drug repositioning', 'drug repurposing', 'drug reprofiling', 'drug redirecting' and/or 'drug rediscovery'. Only 67 included a definition ranging from brief and general to extensive and specific. No common definition was identified. Nevertheless, four common features were found: concept, action, use and product. The different wording used for these features often leads to essential differences in meaning between definitions. In case a clear definition is needed, for example from a legal or regulatory perspective, the features can provide further guidance.